Juniper Networks Juniper Networks Nokia Nokia Cisco Systems Thomson Reuters This document specifies general rules for interaction between the BAR (BIER Algorithm) and IPA (IGP Algorithm) fields defined in ISIS/ OSPFv2 Extensions for BIER. The semantics for the BAR and IPA fields (when both or any of them is non-zero) defined in this document updates the semantics defined in RFC8444/RFC8401.